Stroke is the second leading cause of death worldwide and the leading cause of death in China. The majority of strokes in China and worldwide are due to intracranial atherosclerosis (ICAS). Despite the enormous public health impact of ICAS, the pathophysiology of ICAS is not well understood and the risk of stroke is high despite available treatments. High resolution (HR) MRI has emerged as a potential tool to study the pathophysiology of ICAS and the response to treatment in vivo. However, in order to advance the field of HRMRI ICAS research, establishment of an international multicenter network to provide the research infrastructure for promoting collaboration, sharing of protocols and data, and providing a quick and efficient mechanism for studying HRMRI in ICAS is needed. We aim to develop such a collaborative international HRMRI ICAS research network in China and North America by initially establishing a Central Coordinating Center in Beijing that will lead 10 China sites. In this proposal we aim to: 1. Assess current research needs and capabilities to perform valid and reliable HRMRI sequences in China, 2. Establish the necessary research infrastructure to perform international multicenter HRMRI ICAS imaging, including establishing reliable image quality at the sites by using an innovative imaging phantom, and 3. Plan, prepare, and obtain preliminary data for the design of a multicenter international study that will evaluate the relationship between HRMRI plaque features and recurrent stroke risk and how currently available medical therapy, such as statins, influences that relationship. By achieving these aims we will develop a sustainable collaborative international HRMRI research network that will provide a platform for future HRMRI studies. This will provide new insights into the pathophysiology of stroke due to intracranial atherosclerosis, which we expect will lead to new preventive treatments for the leading cause of stroke in China and worldwide.